The objective of this study remains twofold; namely 1) To evaluate prostatic fluid to develop a simple means of identifying men with a high risk of carcinoma of the prostate; and 2) to assess the value of pelvic lymph node and pelvic marrow studies in staging carcinoma of the prostate. Prostatic Fluid Studies - Lactic dehydrogenase (LDH) isoenzymes: Summaries of our experience with LDH isoenzyme determination in prostatic fluid of men were the subjects of two publications during the grant year. Prostatic fluid from patients with prostatic inflammation showed the predominance of the LDH-V isoenzyme characteristic of malignancy. An LDH-V/LDH-I ratio of 2 or over was observed in prostatic fluid of more than 80% of patients with prostatic carcinoma, approximately 12% of the men with BPH and none of the men under 45 years of age without evidence of prostatic inflammation. C3 C4 transferrin immunoglobulins: During the past year, we have attempted to identify and quantify specific immunoproteins in the prostatic fluid. Preliminary results of this study have been assembled in a manuscript prepared for publication. An increased transferrin, C3 and C4 concentrations in patients with carcinoma of the prostate has been noted. Pelvic Node - Pelvic Marrow Studies: The data on the first 60 patients have been summarized in a paper by Dr. Ronald Sadlowski that was awarded a prize by the American Urological Association. The studies have been continued with patients for marrow biopsy and enzyme studies accumulating at a much reduced rate as the result of the original assessment became known. In the period covered by this report, 23 additional bone marrow studies have been done. Dr John Babcock has just reviewed the morbidity experience by 100 consecutive patients undergoing pelvic node excision. This report will be sumitted for publication soon.